Using stent grafts to treat aneurysms is common in the medical field. Stent grafts are deployed by accessing a vasculature with a small incision in the skin and guiding a delivery system to the target area. This intraluminal delivery is less invasive and generally preferred over more intrusive forms of surgery. Multiple stent grafts may be implanted using intraluminal delivery to provide a system of interconnected stent grafts. Stent graft systems can be made of fenestrated stent grafts and smaller side branch stent grafts, including bifurcated components.
Aneurysms sometimes affect a vessel and its branch vessels, such as the aorta and the renal arteries or the aortic arch and the branch arteries. In such instances, a fenestrated graft can be implanted in the main vessel while smaller branch grafts can be deployed in the branch arteries. The main vessel grafts have fenestrations that correspond with the openings of the branch vessels. The smaller branch grafts are joined with the main vessel graft at the fenestrations. An additional distal graft can be implanted at the distal end of the main vessel graft, where the distal graft can be in the form of a single tube or be bifurcated to include a pair of leg portions that extend into the iliac arteries.
When the smaller branch grafts are deployed through the main graft fenestrations and into the branch arteries, portions of the branch grafts can remain disposed within the main vessel graft, extending partially across the lumen of the main graft. When the distal graft is subsequently introduced into the vessel and delivered to the main vessel graft and branch grafts, the delivery system of the distal graft can contact and possibly crush the branch grafts disposed within the main vessel graft. This can damage the branch grafts which can require time consuming repair or removal and re-deployment.